The purpose of this study is to measure cerebral blood flow with positron emission tomography (PET) and H2150 (while subjects are listening to scripts about their own traumatic childhood events) in patients with childhood abuse-related posttraumatic stress disorder (PTSD) and subjects with a history of abuse but without PTSD. We hypothesized that exposure to traumatic reminders, in the form of listening to recordings of the subjects own childhood traumatic memories, in the PTSD patients, an increase in blood flow in specific areas, in and in comparison to blood flow during exposure to neutral recordings and in comparison to blood flow in healthy subjects during exposure to trauma-related recordings. Initial results show a failure of activator in medial prefrontal cortex which may underlie symptoms in PTSD.